AuthorTopic: ESC (Read 4913 times)

Angus64

Hi. Today I fitted my rudder sevo everything is going well, Still waiting for my ESC to arrive from Hong Kong. I am using a 12 volt 10 amp hour gel battery and I am wondering if someone can tell me where the current gets broken down to operate the servo & receiver I understand they are lower voltage around the 7 Volt. I don't want to blow things up so I thought it best to find out what happens. Thank to anyone who might be able to shed a little light on this subject for me.

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nick_75au

The voltage required by the servo and receiver is 4.8-6 volts, this is usually supplied by a 4 cell AA pack. If your ESC has BEC (Battery Elimination Circuit) then the ESC will supply the receiver and servo through the ESC's receiver connection wire. In this case don't use the extra 4 cell battery.

In the case of BEC all you need to do is plug in the servo and ESC receiver connection to the receiver (duh) then connect your motor to the ESC motor output and connect the 12 volt battery to the ESC power input, the ESC then supplies the correct voltage to the rest of the system.

Angus64

Thanks Nick. I said I knew nothing about electronics in my first post, I guess I just made that even clearer. But you have helped me out again, I can see what happens now, So I will keep on working with my bunch of wires & hope everything works for me. If I get stuck it will be back to the forum with more Questions. Normal Wiring around autos or boats I don't have a problem with, Electronics is a different thing altogether I still have to get my head around that one.Angus.

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Angus64

Hi Boys. I received my ESC today, But not certain about the specifications so I thought I should get back to the forum & ask a few questions. The input says 6V-8.4DC (1/10 ESC) is this the amount put out by the ESC or the amount of power (volts) that can be put into the ESC, I can understand the BEC:5V 1A. I have put the Specifications below.Hope there is someone out there that is willing have a go at explaining those to me.

nick_75au

INPUT:6-8.2 V DC that means can have an input voltage of 6-8.2 volts which basically means a 5 to 7 cell Ni-XX pack ( so its really designed for 6 cell RC buggy packs) The 12 volt Gel cell mentioned in your first post has too high voltage. DC is Direct Current i.e. from a battery

5v 1A, BEC is the output through the servo connector to the receiver its 5 volts and 1 amp, 1 amp is enough to run the receiver and 1 or 2 servos)

20A forward is the maximum current the motor is allowed to draw, you can ignore the 300A (spark) rating, for info its the theoretical maximum/ peak the ESC can handle momentarily. in reality don't exceed 20 amps.

Applicable:540/20T motor and above, ts designed for buggies and they classify motors by the number of Turns (20T) on the armature the more turns the slower the motor (and the more appropriate for most scale boats)

I don't know how well you understand electrical theory but an analogy can be water in a pipe, voltage is the pressure, Amps is the volume, too high a voltage(pressure and the pipe bursts) to small a pipe and the volume(amps) are restricted.

Angus64

Thanks Nick. I had better look for another ESC in that case I have the 12 volt battery fitted, But you have explained that very well, I will get there eventually if I keep trying. I might give the cheap Chinese electronics a miss, They don't explain things very well.

Angus64

Thanks to all who have given advice on ESC, Can anyone advise me on a ESC that will handle a 12 Volt 12 amp hour battery, I have a 12V 12AH sealed lead acid gel battery installed in my boat, But there so many ESC's out there & so many conflicting ideas that it makes it difficult to know which one will best do the job,I don't want to spend a fortune on on ESC's , This is my first boat so I am working in the dark a bit, Any advise would very much appreciated.

rathikrishna

Hey Respected modeler..you can simply make an ESC with BEC, within an hour, by using the ic 555 and two or three IRFZ 48 MOSFETs.. will haul up to 50 amps..and can boost the BEC up to 5 amps, with 4.6 or 5 or 6 volts..adjustable..will work from 6 volts to 18 volts..will within about 4 dollars..make it..fix it..run it..

The important things to consider are 1. the battery voltage. The capacity of the battery is relatively unimportant, it determines run time.2. the power required. This is affected by the motor used, but also by the load imposed on the motor by the choice of prop.A large (10 or 12AH SLA) makes me think of a fairly large displacement hull, and this in turn points to a relatively large prop with a fairly large motor with a lot of poles. Not high speed, but lots of torque.

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"With the right tool, you can break anything" - Garfield

Angus64

Thanks boys for replying to my post. I should of included more information in my last post, My boat is a big one at 1.5 mts, A model of my own design built from the dimensions of a 85 foot fishing boat I maintained for 30 years I was a marine Diesel fitter now retired, but there was no electronics in what I worked on I have a 12 volt 300 watt motor turning an 80mm 4 blade Raboesch propeller, Malcolmfrary you are on the right track when you say fairly large displacement hull, Hope this can help with solving my ESC problem I am having.

nick_75au

If you are operating the motor at its rated power of 300 watts then the motor will draw 25 amps (300 /12), do you happen to know the no load RPM or if not do you have a multimeter and a drill press with a known RPM to do a test ?

Nick

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Angus64

Thanks Boys for the advice it is much appreciated. I will check the ESCs out & see what I can sort out there is a lot of them out there to choose from but I don't want to buy the wrong one again. I noticed there are a lot of Buggy & car ESCs to that might be Ok if they were kept dry, Has anyone tried them in boats I thought the Novak Super Rooster sounded as if it would do the job, Any thoughts on that one I have listed below.

6. Will water cooling be required? ( Usually applied to power boats. )

7. What connectors does it come with? ( Am I happy changing, soldering different connectors as required? )

8. What manufacture has "best" reputation? What do others recommend on here? ( Buy one of these! )

9. What am I willing to spend?

10. Buy the cheapest ESC I can possible find on Fleabay. Burn it out. Rant at poor Chinaman that sold it to me. Get another one sent from China. Burn that out too. Swear and curse all Chinese take-aways as I wait for the the smoking boat will drift back in and hopeit reaches shore before it sinks. Throw boat to back of shed. Resurrect said boat from back of shed a year later, having conveniently forgotten where I got the unlabelled ESC from. Buy another one from Fleabay, get lucky and sail way past sunset on a warm Sunday evening wishing I had better low end control. Go back to step 10 and do that!

Angus64

Hi boys. I had a goods look at Action electronic , Sent him all the specification of the motor & prop size ect. He is easy to deal with & answered any questions I had & prices are good. So I took Timo2's advice and went with Action electronic,He sent them air freight so they should be here soon. Thanks to all who took the time to reply & give there advice it is much appreciated.